ERBBands¶

standard mode | Spectral category

Inputs¶

spectrum (vector_real) - the audio spectrum

Outputs¶

bands (vector_real) - the energies/magnitudes of each band

Parameters¶

highFrequencyBound (real ∈ [0, ∞), default = 22050) :
an upper-bound limit for the frequencies to be included in the bands

inputSize (integer ∈ (1, ∞), default = 1025) :
the size of the spectrum

lowFrequencyBound (real ∈ [0, ∞), default = 50) :
a lower-bound limit for the frequencies to be included in the bands

numberBands (integer ∈ (1, ∞), default = 40) :
the number of output bands

sampleRate (real ∈ (0, ∞), default = 44100) :
the sampling rate of the audio signal [Hz]

type (string ∈ {magnitude, power}, default = power) :
use magnitude or power spectrum

width (real ∈ (0, ∞), default = 1) :
filter width with respect to ERB

Description¶

This algorithm computes energies/magnitudes in ERB bands of a spectrum. The Equivalent Rectangular Bandwidth (ERB) scale is used. The algorithm applies a frequency domain filterbank using gammatone filters. Adapted from matlab code in: D. P. W. Ellis (2009). ‘Gammatone-like spectrograms’, web resource [1].

References:

[1] http://www.ee.columbia.edu/~dpwe/resources/matlab/gammatonegram/

[2] B. C. Moore and B. R. Glasberg, “Suggested formulae for calculating auditory-filter bandwidths and excitation patterns,” Journal of the Acoustical Society of America, vol. 74, no. 3, pp. 750–753, 1983.

Source code¶

C++ source code

C++ header file